Valved air hose spud for paint spray guns



June 26, 1951 5 w. w. cuLLl-:N

VALVED AIR HOSE SPUD FOR PAINT SPRAY GUNS Filed Jan. 20, 1950 Mmmm@ ATTORNEY` iatentecl June 26,

UNiTEo (stares saresti* orifice VALVED AIR HSE SPUD FOR PAINT SPRAY GUNS William' vv. oulien, Baltimore, Mii., assigner to lack Manufacturing Company, Parlston, Md., a corporation of Maryland Appiieation January 20, i950, serial Ne. 139,567

y(ci. isa-42) 14 Claims. 1

This invention relates to paint spray guns and more especially to apparatus for removing moisture and other foreign matter from the gun carried thereinto with the compressed air employed for atomizing the paint. Particularly the invention relates to spuds for attaching the compressed air hose to the gun, said spud incorporating means forming a liquid trap and a discharge valve for periodically discharging accumulated liquid and other foreign matter from the trap.

In paint spray guns, compressed air is employed to eject paint in a stream from the nozzle of the gun and to atomize this stream in a line mist of controlled form or pattern. The air is supplied from an outside source usually through a hose connected with an air passage extending inwardly through the handle of the gun. This air, particularly when compressed from the atmosphere, contains considerable' moisture and often dust and other foreign particles' which, unless removed, detrimentally ailect both the gun and the paint coat applied by the gun.

I am aware that suggestions have heretofore been made, such as in Hermann Patent 1,822,622, for baiiiing, screening or ltering the undesirable material from the air as it enters the gun and before it reaches the spray nozzle and removing accumulation of this material periodically from the gun body. rlChis invention is an improvement particularly in the means for such removal of accumulated moisture and other undesirable material which has been separated from the air stream entering the spray gun.

For best results and for proper normal operation of the spray gun, the means for discharging accumulation of foreign matter separated from the air must be easily accessible and quickly and easily operated by the user of the gun, but must at all times, even after extended and repeated use, provide a tight air seal to obtain efficient normal use of the gun.

It is an object of this invention, therefore, to provide a spud for connecting a compressed air hose to the entrance of the air passage of a paint spray gun, the spud incorporating a novel valve construction for discharging accumulations of foreign matter removed from the air entering the gun, the valve being readily accessible and easily operated but forming a tight air seal which will prevent leakage of air during normal operation of the gun. v

Another object of the invention is to provide a Spud of the above character which is a separate part from the gun itself and may be used with various types of commercial spray guns.

Another object of the invention is to provide a Spud of the above character which also incorporates a built in tubular extension' of smaller diameter than the air passage entering the gun, which extends into' the air passage' when the Spud is attached to the gun, and forms, with the entrance to the air passage, a Well or trap for the collection of removed moisture and other matter removed from the air.

A further object of the invention is' to provide a device of the above character whichis economical to manufacture but is positive in operation and subject to a long life of repeated use.

With the above and other important objects and advantages in View, which will become more apparent during the course of the following description, the invention consists in the parts and combinations hereinafter set forth with the understanding that various/changes may be made therein by those skilled in the art,such as in the size, shape and arrangement of the parts or by the substitution of equivalents, without departing from the spirit of the invention.

In order to make the invention more clearly understood, preferred embodiments thereof have been made the subject of illustration in the accompanying drawings in which:

Figure l is a side elevational view, partly in vertical transverse section, of a paint spray gun provided with a baiiie means in the air passage in the gun handle and illustrating one form of valved spud according to this invention attached thereto;

Figure 2 is a longitudinal sectional view in perspective of the spud shown in Figure l with the air tube removed;

Figure 8 is a view similar to Figure 2 of a modied form of spud'; and

Figure 4 is a View similar to Figure 2 of a further modified form of spud.

Referring more particularly to the drawing, there is shown in Figure l a paint spray gun I of conventional design, comprising a frame or body 2, having an atomizing nozzle 3 and a handle il. Compressed air is admitted to the gun body through a. straight passage 5 extending upwardly through the handle 6l from the lower end thereof to a cross passage 6 in which is positioned an air valve, not shown but operated by means of a stem l actuated by a pivoted trigger 8. From the air valve other air passages (not shown) extend through the body forwardly to the nozzle 3 Where the air serves to eject and atomize a stream of paint admitted to the body through a spud 3 which connects through passages with a paint orifice in the nozzle controlled by a valve l5, also actuated by the trigger 8 in usual manner.

In order to prevent moisture and other foreign matter contained with the entering air from reaching the nozzle there is provided a iilter or baie unit, indicated generally as ll, in the air passage 5. lThe baille unit illustrated consists of a tube l2 tting closely within the upper end of the passage against a shoulder i3 and is retained against accidental displacement by means of a spring ring I4 pressing against the wall of the passage and against the lower end of the tube I2. At opposite ends of the tube i2 there are secured small discs l5 of fine mesh screen between which is a loosely packed baiiling or filtering material I6 such as metal wool. As in usual construction the entrance end of the air passage 5 is somewhat enlarged and internally screw threaded to form a socket l1 for the reception of a spud to connect the air passage with a compressed air hose'shown in dotted lines in Figure 1 and indicated generally as IS.

I'he spud according to the form o the invention shown in Figures 1 and 2 comprises a tubular body I9 having an upper extension 20 which is externally screw threaded to fit within the socket Il'. The top of the extension 2E! is formed with a face 2i to seat in sealing engagement with a shoulder 22 at the inner end of the socket I1. The lower end of the body I9 is formed with an externally screw threaded extension 23 to t a coupling member 24 of the hose i8 while between the extensions 23 and 24, the spud body is formed with an external radial flange 25 the periphery of which may be shaped hexaginally for screwing the spud into the socket l1. The lower face of the ange (toward the extension 33) forms a conical surface 25 converging toward the periphery of the extension 23.

The inner surface of the tubular body I9 is in the form of a stepped bore, the larger diameter portion 21 extending downwardly from the face 2| to the vicinity of the flange 25. Here the bore converges in a conical shoulder 28 to a smaller diameter portion 29 which extends downwardly to adjacent the end of the extension 23 where it flares outwardly to form a conical seat 30. Drilled inwardly from the conical face 26 of the flange through to the shoulder 28 are one or more radial ports 3i.

Screw threaded on the extension 23 is an upwardly opening cylindrical cup 32, coaxial with the body I9 and having positioned therein an annular washer 33 composed of soft rubber, or equivalent compressible material, having a conical upper face 34 which seats with the face 26, when the cup is screwed upwardly on the extension 23, to close the outer ends of the ports 3|. The circumferential periphery of the cup 32 may be knurled or otherwise suitably formed to facilitate turning with the ngers and it will be noted that the screw threaded extension 23 is of sufficient length to permit the washer 33 to be unseated from the face 25 when the hose coupling 24 is attached to the spud.

As seen in Figure 1 the Spud IS is fitted with a tube 35, the lower end 3B oi which is a close t within the smaller diameter portion 29 of the Spud bore. The lower extremity of the tube is flared outwardly to it the seat 30 to prevent displacement of the tube and provide a leak proof joint with the hose coupling 24. At the internal shoulder 28 of the spud bore, the tube 35 converges to a smaller diameter extension 3'! which extends centrally through the larger diameter portion 21 of the spud bore, upwardly and centrally into the air passage 5. As will be seen in Figure l the extension 3i of the tube is spaced radially inwardly from the inner surface of the passage 5 and the spud bore 2 and forms an annular well or trap 39 the bottom of which is the shoulder 28 having therein the ports 3l.

In operation, when the air Valve of the spray gun is opened, air enters the passage 5 through the tube 35 and moisture and other particles carried with it are separated from the air stream as it enters the filter element Il. This separated material ows downwardly along the inner wall of the passage 5 and into the annular well 39 where it is trapped and accumulates, out of the air stream entering the gun. Periodically during the use of the gun, the operator unscrews the cup 32 moving it downwardly on the spud extension 23 which unseats the washer 33 and opens the ports 3|. Now, with the air valve of the gun closed, the pressure of air in the passage 5 blows the accumulation out of the well 39 through the ports 3l. When thus emptied, the cap is again tightened to reclose the ports 3| and the gun is again ready for use.

In the form of valved spud shown in Figure 3 the spud body ISA is formed with opposite screw threaded extensions 25A and 23A similar to the extensions described above except in this case the extension 25A is the longer of the two, and an intermediate hexagonal flange 25A. The extension EGA, immediately adjacent the ange 25A is diametrically enlarged and externally screw threaded, as indicated at 4B. In the peripheral surface of the enlargement 45, adjacent the contiguous face of the flange, there is formed a circumferential groove 4I 'from the bottom of which one or more radial ports 42 are drilled inwardly through the shoulder 28A between the larger and smaller diameter portions 21A and 28A of the spud bore. The spud I9A may be tted with an axial tube 35 in the manner described above.

To open and close the ports 42 there is provided a downwardly opening cylindrical sleeve 43 the cylindrical wall of which is internally screw threaded to be screwed on the enlarged portion 4U with the extension 20A projecting through an internal flange 44 on the upper end of the sleeve. The opposite or lower end of the cylindrical Wall of the sleeve 43 is formed with a flat face which when the sleeve is screwed downwardly seats on an annular washer 45 of rubber or other suitable compressible material which is held in an annular groove 45 in the upper face of the iiange 25A. A compressible packing washer 41 is placed about the extension 20A to engage the inner face of the flange 44 and upper face of the enlargement 4D when the cup member is screwed downwardly to form a seal between the sleeve and Spud extension.

The form of valved spucl shown in Figure 4 is somewhat similar to that shown in Figure 2 comprising a body ISB having screw threaded extensions 20B and 23B and a hexagonal flange 25B. The interior of the body is step bored in the manner described above to form larger and smaller portions 21B and 29B and an internal shoulder 28B. Ports 48 extend radially from the shoulder 28B to the lower surface 49 of the flange 25B. The lower surface 49 of the iiange in this case is perpendicular to the axis of the spud rather than being conical as in Figure 2.

To open and close the ports 48 there is provided an annular compressible washer 5i) which surrounds the extension 23B and lies between the lower face 49 of the flange and a ring 5I screw threaded on the extension 23B. This spud is likewise adopted to be tted with the tube and both this and the form shown in Figure 3 are fitted to the spray gun in the manner shown in Figure 1.

Commercial spray guns are usually machined for s tandard ttings and the valved spuds embraced in this invention may likewise be machined to accepted standards to intert with different commercial guns Without change other than substitution of the valved Spud for the standard fitting and inserting a lter capsule vof the type shown or other suitable baifling material in the air passage in the gun handle.

In each of the embodiments above described it will be seen that the finger engaging member for opening and closing the discharge ports is readily accessible and is of relatively large diameter for ease in loosening and positively tightening. The

compressible washer seals and the large seating surfaces provid-ed assure positive sealing over extended periods of repeated use. It will be noted, moreover that the port closing member is moved between the enlarged attaching flange of the Spud and either the end of the gun handle or the air hose coupling unit so that in use it cannot be completely removed from the spud and lost.

rIhis invention is described in connection with paint spray guns, but it will be obvious that it may be used with spray guns for applying other coating materials such, for example, as dock bronzing powders and like materials which are detrimentally aiected by moisture.

I claim:

l. In a paint spray gun having an air passage and means therein for separating moisture and other foreign matter from air entering said passage, a spud comprising a tubular body having screw threaded extensions thereon for attachment respectively into said passage and to a coupling element of an air hose, said body having at least one port extending from the interior of the body to the exterior thereof adjacent one of said extensions, a seating surface formed exteriorly on the body adjacent the exterior end of the port, a member screw threaded on said one extension for movement toward and away from said surface, anda compressible sealing element between said member and surface and seated therebetween to close said port when said member is screwed. toward said surface.

2. In a paint spray gun having an air passage and means therein for separating moisture and other foreign matter from air entering said passage, a spud comprising a tubular body having screw threaded extensions thereon for attachment respectively into said passage and to a coupling element of an air hose, said body having an axial bore therethrough having a circumferentially larger portion adjacent the end attached in said passage and a circumferentially smaller portion adjacent the opposite end and an internal shoulder between said portions, a tube positioned axially in said bore and closely tting said smaller portion, said tube being spaced radially from the larger portion of said bore and forming therewith an annular well for the reception of separated material from said passage, at least one port extending from said shoulder to the exterior of said body adjacent one of said extensions, a seating surface formed exteriorly on the body adjacent the exterior end of the port, a member screw threaded on said one extension for movement toward and away from said surface, and a compressible sealing element between said member and surface and seated there between to close said port when said member is screwed toward said surface.

3. Apparatus of the character set forth in claim 2 in which the portion of the tube extending from said shoulder through the larger portion of the bore is of smaller diameter than the portion thereof tting within said smaller portion of the bore.

4. Apparatus of the character set forth in claim 2 in which the tube extends through the larger portion of the bore and beyond said body to extend substantially into said passage concentrically therewith when the spud is attached into said passage, the Said extension of the tube being of a diameter smaller than the diameter of the passage.

5. In a paint spray gun having an air passage and means therein for separating moisture and other foreign matter from air entering said passage, a spud comprising a tubular body having screw threaded extensions thereon for attachment respectively into said passage and to a coupling element of an air hose, said body having an external radial nange between said extensions and forming an annular face contiguous to the extension attached to the air hose, ports extending from said face to the interior of said body for discharging separated material from said passage, an annular member screw threaded on said last named extension, and a compressible Washer element surrounding said extension between said annularv member and face to be compressed into sealing engagement with said face by screwing the annular member in one direction to close the ports and to open said ports when said member is screwed in an opposite .direction.

6. In a paint spray gun having an air passage and means therein for separating moisture and other foreign matter from air entering said passage, a spud comprising a tubular body having screw threaded extensions thereon for attachment respectively into said passage and to a coupling element of an air hose, said body having an external radial ange between said extensions and forming a frusto conical face contiguous to the extension attached to the air hose, ports extending from said face to the interior of said body for discharging separated material from said passage, a cup shaped annular member screw threaded on said last named extension coaxially therewith, said cup shaped member opening toward said flange, and a compressible washer element carried in said member and having a conical surface complementary to said face to be seated thereon and close said ports when said member is screwed in one direction and moved away from said face to open the ports when said member is screwed in an opposite direction.

7. Apparatus of the character set forth in claim 6 in which the said tubular body is formed with a stepped axial bore therethrough having a circumferentially smaller portion in the extension attached to the air hose and a circumferentially larger portion in the extension attached in said air passage and an internal shoulder connecting said bore portions, the ports extending from said face to said shoulder, and a tube extending axially through said bore and f1tting closely within said smaller portion and being spaced radially inwardly from the larger portion.

8. Apparatus according to claim '7 in which the tube extends beyond said body and substantially into said passage concentrically therewith, when the Spud is attached into said passage the extension of the tube being of a diameter substantially less than the diameter of the passage.

9. In a paint spray gun having an air passage and means therein ior separating moisture and other foreign matter from air entering said passage, a spud comprising a tubular body having screw threaded extensions thereon for attachment respectively into said passage and to a coupling element of an air hose, said body having an externally screw threaded enlargement between said extensions, said enlargement having an external radial flange and a circumferential groove adjacent the ange, ports extending from said groove to the interior of said body, a compressible Washer seated on said flange and surrounding said groove, a sleeve member screw threaded on said enlargement and having an end seating on said washer when the sleeve is screwed in a direction toward said iiange to close the groove to the atmosphere, said sleeve having an internal flange overlying said enlargement and a compressible sealing gasket between said internal ange and enlargement.

10` Apparatus of the character set forth in claim 9 in which the tubular body is formed with a stepped axial bore having a circumferentially smaller portion at the end attached to the air hose and a circumferentially larger portion at the opposite end and an internal shoulder, connecting said portions, said ports extending from the groove into said larger portion immediately adjacent the shoulder and a tube extending axially through said bore and Fit-ting closely within said smaller portion and being spaced radially inward from the larger portion.

11. In a paint spray gun having an air passage and means therein for separating moisture and other foreign matter from entering said passage, a spud for attachment into said air passage having a bore therethrough opening into said air passage, said spud having an extended portion exterior of said spray gun, at least one port extending from said bore to the atmosphere at said extended portion, valve means normally closing said port, and means for attaching an air hose to the extended portion of said spud so that air will enter the air passage through said bore.

12. In a paint spray gun having an air passage and means therein for separating moisture and other foreign matter from entering said passage, a spud for attachment into said air passage having a bore therethrough opening into said air passage, said stud having an extended portion exterior of said spray gun, at least one port extending from said bore to the atmosphere at said extended portion, a tube having one end seated in said bore immediately below the port extending from said bore and the other end extending up into said air passage, said tube being f lesser diameter than the bore so that liquid will accumulate in the bore around the outside or the tube, valve means normally closing said port, and means for attaching an air hose to the extended portion of said spud so that air will enter the air passage through said bore.

13. In a paint spray gun having an air passage and means therein for separating moisture and other foreign matter from air in said passage, a spud for attachment into said passage, said spud .having an extension exterior of said gun for attaching an air hose toward the end thereof, an external ange on said extension between the gun and the end of the extension, a bore extending through said spud, ports extending through said flange to the bore for discharging separated material from said passage, and a valve on said extension to be pressed into sealing engagement with said ports in said liange.

14. In a paint spray gun having an air passage and means therein for separating moisture and other foreign matter from air in said passage, a spud for attachment into said passage, said spud having an extension exterior of said gun for attaching an air hose toward the end thereof, an external flange on said extension between the gun and the end of the extension, a bore extending through said spud, ports. extending through said iiange to the bore for discharging separated material from said passage, a tube having one end seated in said bore immediately below the port extending from said bore and the other end extending up into said air passage, said tube being of lesser diameter than the bore so that liquid will accumulate in the bore around the outside of the tube.

WILLIAll/I W. CULLEN.

REFERENCES CITED The following references are of record in the lile of this patent:

UNITED STATES PATENTS Number Name Date 1,644,081 Preble Oct, 4, 1927 1,706,006 Thompson Mar. 19, 1929 1,910,014 Hermann May 23, 1933 

